William johnstoke



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W. JOHNSTQNE.

-STEAM BOILER.

No. 247,920. PatentedOct. 4,1881.

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UNITE STATES,

' PATENT OFFICE.

STEAM-BOILER.

SPECIFICATION forming part-0f Letters Patent No. 247,920, dated October4, 1881.

Application filed July 22, 1881. (No model.) Patented in Canada May 26,1880.

To all whom it may conccrh Be it known that I, WILLIAM J OHNS'IONE,ofOttaw-a, in the county of Carleton and Province of Ontario, Canada,have invented a new and Improved Steam-Boiler, of which the following isa specification.

The object of this invention is to provide a cheap and efficient boilerfor generating steam for mechanical purposes, for heating dwellings, andother purposes; and theinvention consists of a boiler or steam-generatorhaving a waterchamber with drop-tubes forming the top of the boiler,which top is connected by vertical tubes to an annular chamber formingthe base of the boiler. The fuel-entrance is obtained by shortening therequired number of tubes from top and bottom, and the grate-bars arewithin the circumference of the annular base.

In the accompanying drawings, Figure 1 is an elevation of my improvedboiler with the front of the casing or jacket removed, and also some ofthe tubes, in order to exhibit other parts. Fig. 2 is a verticalsectional elevation ofthesame, with parts removed to exhibit otherparts. Fig. 3 is a cross-section of the boiler on line y y, Fig. 1.

Fig. 4 is a cross-section of the boiler on the line new, Fig. 1.

Similar letters of reference indicate corresponding parts.

In the drawings, A represents the cylindrical upper section or chamberof the boiler for containing water and steam, from which chamber A, andcommunicating therewith, drop-- tubes B, for containing water, dependinto the fire-chamber O.

The tubes B gradually increase in length from the center of thesaidchamber A outward to the row of circulating-tubes E, and the longestones of which extend a little more than half-way the distance betweenthe said chamber and the grate, as shown in Fig. 2.

E E represent water-circulating tubes extending from near thecircumference of the upper chamber, A, into the annular chamber D, thatforms the base of the boiler, said tubes E E thereby forming theexterior wall of the boiler.

Within the circumference of the chamber or base Dis fixed the grate F,pivoted on a cross-bar, G, or other suitable device, to allow said grateF to be shaken to clear the fire. The ashes from the fire are designedto fall into the pit H.

The fuel is introduced into the fire-chamber 0 through an opening, I,which is formed by The drop-tubes B K, being closed at their lower ends,cause ebullition in the chamber A, and the said tubes are set far enoughapart for the products of combnstionto circulate freely between them.

N represents the casing or jacket of the boiler, of cylindrical shapeand constructed of iron or brick, as may be desired, being of brick inthis case. Said casing or jacket N is enlarged at the top about the topsof the tubes E E and chamber A, thereby forming an annu lar flue, asshown at 0, completely inclosing said chamber A, and causing theproducts of combustion from the fire-chamber O to circulate about it,passing horizontally between the tubes, and thence vertically up thesides of the chamber A and over its top, as indicated by arrows, Fig. 2.

The sides of thejacket or casingN are carried up above the chamber A andcovered by a plate, P, from the center of which extends the smoke-pipeQ.

R represents the feedwater pipe for conducting water to the chamber D,and S represents the pipe for carrying off the steam or hot water.

'Having thus' fully described my invention, I claim as new and desire tosecure by Letters Patent- In a steam-boiler, the combination, with thecylindrical chamber A, arranged above the fire-chamber, and the annularchamber D, surrounding the grate, of the drop-tubes B K, theconnecting-tubes E, the short tubes L, and the horizontal pipe M,substantially as and for the purpose set forth. V

The above specification of my improvement in boilers for generatingsteam or heating water signed by me this 5th day of July, 1881.

' WILLIAM JOHNSTONE.

Witnesses:

E. H. BRONSON, S. FRUNNELL.

